write-intent bitmaps

[Bill Davidsen]

Russell Coker wrote:
> On Sunday 27 January 2008 22:21, Neil Brown <neilb at suse.de> wrote:
>   
>> On Sunday January 27, russell at coker.com.au wrote:
>>     
>>> http://lists.debian.org/debian-devel/2008/01/msg00921.html
>>>
>>> Are they regarded as a stable feature?  If so I'd like to see
>>> distributions supporting them by default.  I've started a discussion in
>>> Debian on this topic, see the above URL for details.
>>>       
>> Yes, it is regarded as stable.
>>     
>
> Thanks for that information.
>
>   
>> However it can be expected to reduce write throughput.  A reduction of
>> several percent would not be surprising, and depending in workload it
>> could probably be much higher.
>>     
>
> It seems to me that losing a few percent of performance all the time is better 
> than a dramatic performance loss for an hour or two when things go wrong.
>
>   
You may have missed the "much higher" part of the previous paragraph. 
And given the reliability of modern drives, unless you have a LOT of 
them you may be looking at years of degraded performance to save a few 
hours of slow performance after a power fail or similar. In other words, 
it's not as black and white as it seems.

-- 
Bill Davidsen <davidsen at tmr.com>
  "Woe unto the statesman who makes war without a reason that will still
  be valid when the war is over..." Otto von Bismark 


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